Transcript Title of Presentation - Broadband Home Central

Wireless Technologies In The
Home – The Invisible Cable
Plant
Sandy Teger and David J. Waks
System Dynamics Inc.
[email protected]
Many Wireless Opportunities
Public places:
Hotels
Airports
Restaurants
In the home
Outside
In the Home
• Technologies
– Wi-Fi®: IEEE 802.11x
– UWB: IEEE 802.15.3a
• Issues
– Applications: data, voice, video
– Useful range
– Speed
– Security
– Robustness – QoS, reliability
Current Wi-Fi® Status
• Three “flavors” of Wi-Fi
– 802.11b: 11 Mbps in 2.4 GHz
– 802.11a: 54 Mbps in 5 GHz
– 802.11g: 54 Mbps in 2.4 GHz
• Effective maximum speed: ~20 Mbps
• Range: comparatively limited at maximum speed,
improving
• Security improving – WPA™ and WPA2™
• QoS improving - WMM™
• Wi-Fi certification will become even more important
– Product complexity is rising
– More chip sets and MAC implementations increase probability of
interoperability failure
– Cost pressures will impact product quality
– Different brands increase interoperability challenge
New Developments
• Focus on 100+ Mbps throughput – many
contending technologies including existing wiring
and wireless (802.11n, UWB)
• Move to “whole home” networking
– Video becoming part of the mix  higher speed & QoS
– HDTV and flat screens taking off; new “entertainment
PCs” emerging  better use of spectrum
– Digital Living Network Alliance (DLNA, formerly DHWG)
developing interoperability standards for integrated
networks
Networked Entertainment
Issues
•Requirements
–Support all media – audio, video, data
–Audio and video need QoS
–HD video needs high bandwidth
–Premium digital content needs DRM
•What media formats supported?
•Who supplies what to end user?
Spectrum: 2.4 GHz
• Most consumer products use 2.4 GHz
– Shared by 802.11b and 11g
– Interference from microwaves, portable
phones, and neighbors
• Most products default to channel 6
– One of three non-overlapping channels
• Most products default to maximum
transmit power
– Maximize potential for interference with
neighbors
Spectrum: 5 GHz
• Why not use 802.11a/5GHz?
– 12 non-overlapping channels now, 23 soon
– BOM cost differential less than $5
– Vendors getting high margins on SME
products
• Microsoft promoting 11a for Media Center
2005
– Use Media Center Extender to carry video
from MC PC to large-screen TV
Microsoft Supports 11.a for Video
• “How do I connect my
Media Center Extender to
my Media Center PC?”
• “There are two main
ways—via an Ethernet
wired or a wireless
connection. The wireless
connection works best
on 802.11a home
networks.”
– Microsoft FAQs
Speed: 802.11n
• Next generation of Wi-Fi®
• 100 Mbps throughput at MAC_SAP layer
– 4x-5x faster than 11a and 11g
• Protocol improvements
• MIMO antennas
– Multiple Input/Multiple Output
• Projected completion: March 2007
• “Pre-11n turbo mode” products appearing
– Wi-Fi Alliance discourages reference to “pre-11n”
Range
• All wireless systems trade range for speed
– Multiple modulation schemes (like DOCSIS)
– “Loss budget” depends on distance and
obstacles
• Most consumer products operate at much
lower transmit power than allowed by FCC
• Range is improving
– New chips enable higher power and better
receiver sensitivity at consumer pricing
Security: 802.11i and WPA™
• Original WEP (Wired Equivalent Privacy)
– Easy to crack, confusing to set up
– Most consumer networks operate open
• IEEE 802.11i is new standard for security
– Took more than 4 years, published July 2004
– Two encryption mechanisms
• WPA (Wi-Fi Protected Access™)
–
–
–
–
Simpler encryption mechanism
Added to Wi-Fi certification in 2003
In most current products
Download for many earlier WEP products
Security: WPA2™
• WPA2 (Wi-Fi Protected Access version 2™)
– More complex encryption – CPU intensive
– Generally requires newest chips
– Added to Wi-Fi® certification in September
2004
– Already included in many products
• Consumer and Enterprise versions
– Different authentication methods
– Consumer: user-selected “secret” text string
– Enterprise: server-based 802.1x/RADIUS
– Products can include both
QoS: 802.11e and WMM™
• QoS needed for audio, voice, video
• Original Wi-Fi® didn’t have QoS
• IEEE 802.11e is new QoS standard
– Still in process after more than 4 years
– Both “prioritized” and “guaranteed” QoS
• WMM (Wi-Fi Multimedia)
– Prioritized QoS subset of 802.11e draft
– Widely accepted by 802.11e members
– Added to Wi-Fi certification in September 2004
– Already included in some products
WMM™ for Video
Source: Wi-Fi Alliance
QoS: HCCA
• Hybrid Coordination Function Controlled
Channel Access
– Guaranteed QoS subset of 802.11e draft
– Probably needed for HD video
– Ongoing debate in 802.11e “dominated by PC
guys”
– Planned for 2005 if standard completed
UWB: 802.15.3a and W-USB
• Ultra wideband is coming
– FCC approved underlying approach
– Chips and products coming to market in 2005
• Standards are uncertain (competing camps)
• Complements 802.11
– Short range technology – 10 meters, single room
• Wireless USB is most likely initial application
– Replaces wired USB, 480 Mbps goal
– Intel, TI and others behind it
• Wireless 1394 is possible follow-on
– Replaces existing A/V wiring
Concluding Thoughts
• 100 Mbps is coming soon
– 802.11n, UWB, HomePlug AV, etc.
• Need a heterogeneous home network
– Wireless is not a complete “whole home”
solution, except maybe in MDUs
• End-to-end QoS is a major challenge
– Service providers want it
– All QoS efforts appear to be in silos
– DLNA is most likely place for resolution
This Home Network of the
Future…Is Now
Video/Audio
Source
Internet
Gateway /
Router
Multimedia
Server
DSL or Cable
Ethernet; Cat5 Cable and/or Home Plug
Game
Console
HD/SD Tuners,
DVD, DVR, Etc.
11a+11e
Desktop PC or MAC
11g+11e
2.4 GHz
5 GHz
High Definition
Display
VoWLAN
Handset /
PDA
Computer
Standard
Definition
Display
Printer
Computer
Source: Bermai